Swift Selection Search (SSS) is an add-on for quickly searching for selected text in a page using your favorite search engines.
Select some words on a page and a small popup box with search engines will appear above your cursor. Press one and you'll automatically search for the selected text using that engine!
SSS is very configurable. Please open the Firefox Add-ons page (the puzzle piece icon!), then the "Swift Selection Search" options page, and follow the short instructions at the top.
You can define which search engines appear on the popup, the appearance of the icons, what happens when you click them, where the popup appears, whether or not to hide it when the page scrolls, auto copy text on selection, and many more options.
You also get an optional context menu for searching with any of your engines. Or you can disable the popup itself and leave only the context menu. Your choice. :)
ABOUT PERMISSIONS: SSS requires permission to "Access your data for all websites", but this is simply to fix a problem that caused the popup to not work in pages that use frames. It also needs permission to read/write downloads just to be able to export/import your settings in the options page if you wish. Rest assured that SSS does not otherwise read or modify your downloads, does not care about what sites you use, and does not send your data anywhere!
SSS is an open source, free-time project, made by Daniel Lobo (that's me) and with the collaboration of awesome people on GitHub. ;)
If you find any problem or have a suggestion, please read the "Troubleshooting" part of the "Instructions" section (in the SSS options page). If the problem isn't covered there, you can report it to the issues page: